When should we start renal-replacement therapy in critically ill patients with acute kidney injury: do we finally have the answer?

[...]small and unblinded trials would be susceptible to biased co-interventions, such as withdrawal of life-sustaining treatments. Of the 4,466 initially excluded, 42.9% failed to achieve Stage 3 AKI and many were excluded for urgent indications (13.5%) or prior RRT (6.8%). [...]of those with Stage 3 AKI who were excluded, 127 (26.0%) developed an urgent indication after a median (IQR) of 35 (17–68) hours and received RRT, while the remainder did not fulfil randomization criteria. [...]serum urea is influenced by a range of factors other than impaired excretion, including excess protein catabolism, corticosteroid administration, exogenous protein or gastrointestinal bleeding and volume contraction. [...]the thresholds of serum urea did not discriminate patients with urgent indications for RRT: 16.6% of Stage 3 AKI patients had urgent indications developed prior to the delayed criteria being fulfilled, and 33% of patients in the more-delayed strategy developed urgent indications prior to the protocolized serum urea threshold (> 50 mmol/L) was fulfilled.